On neoclassical effects in the theory of magnetic islands
On neoclassical effects in the theory of magnetic islands
复制标题
论磁岛理论中的新古典效应
DOI：
10.1063/1.1775007
复制
发表时间：
2004
影响因子：
2.2
通讯作者：
E. Lazzaro
中科院分区：
文献类型：
--
作者：
A. Smolyakov;E. Lazzaro
新古典粘度通过提供额外的横向电流源来影响磁岛的稳定性，该横向电流有助于磁岛中的净纵向电流。这种新古典纵向电流的一个分量具有类似于具有增强等离子体惯性的离子极化电流的结构，并且之前已被研究过。我们表明，除了新古典惯性项之外，还存在与扰动磁表面内等离子体压力变化相关的附加新古典电流。这种变化可能是由磁性表面上的离子极化漂移和平行方向上的有限热导率引起的。由于等离子体压力变化而产生的新经典电流的贡献与标准离子极化和自举电流项具有相同数量级或更大。新术语将影响磁岛的整体稳定性，并可能为新古典撕裂模式提供新的阈值机制。
Neoclassical viscosity affects the stability of magnetic islands by providing additional source of the transverve electric current contributing to the net longitudinal current in the magnetic island. One component of such neoclassical longitudinal current has a structure similar to the ion polarization current with enhanced plasma inertia and was investigated previosly. We show that in addition to the neoclassical inertia term, there is additional neoclassical current associated with variations of plasma pressure within the perturbed magnetic surfaces. Such variations can be caused by the ion polarization drift across the magnetic surface and finite heat conductivity in the parallel direction. A contribution of the neoclassical current due to plasma pressure variations is of the same order or larger than the standard ion polarization and bootstrap current terms. New terms will affect overall stability of magnetic islands and may provide a new threshold mechanism for the neoclassical tearing modes.